.\"	$NetBSD: factor.6,v 1.9 2004/02/08 13:16:25 jsm Exp $
.\"
.\" Copyright (c) 1989, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Landon Curt Noll.
.\"
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.\" modification, are permitted provided that the following conditions
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.\"    may be used to endorse or promote products derived from this software
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.\"	@(#)factor.6	8.1 (Berkeley) 5/31/93
.\"
.\"
.\" By: Landon Curt Noll   chongo@toad.com,   ...!{sun,tolsoft}!hoptoad!chongo
.\"
.\"   chongo <for a good prime call: 391581 * 2^216193 - 1> /\oo/\
.\"
.Dd February 8, 2004
.Dt FACTOR 6
.Os
.Sh NAME
.Nm factor
.Nd factor a number
.Sh SYNOPSIS
.Nm
.Op Ar number ...
.Sh DESCRIPTION
The
.Nm
utility will factor integers between \-2147483648 and 2147483647 inclusive.
When a number is factored, it is printed, followed by a
.Dq \&: ,
and the list of factors on a single line.
Factors are listed in ascending order, and are preceded by a space.
If a factor divides a value more than once, it will be printed more than once.
.Pp
When
.Nm
is invoked with one or more arguments, each argument will be factored.
.Pp
When
.Nm
is invoked with no arguments,
.Nm
reads numbers, one per line, from standard input, until end of file or error.
Leading white-space and empty lines are ignored.
Numbers may be preceded by a single - or +.
Numbers are terminated by a non-digit character (such as a newline).
After a number is read, it is factored.
Input lines must not be longer than 255 characters.
.Sh DIAGNOSTICS
Out of range or invalid input results in
an appropriate error message
being written to standard error.
.Sh BUGS
.Nm
cannot handle the
.Dq 10 most wanted
factor list.
